We have had no problem re-using Northern (or Southern) blots on either
Hybond N+, Gene Screen Plus or Nytran Filters. We strip them by boiling for
5 min or so either in dH2O or 0.5% SDS. We cross-link the blots with UV just
after blotting (200uW/cm^2 for 13 min). We have been able to re-use our blots
4-5 times without any problem (signal strength does fall a little @ each use).
Perhaps your problem lies in cross-linking the RNA to the filter and when you
strip the blot everything goes. We have never used the alkaline fixation
method for Northern/Southerns so I can't tell you if that is inferior to the
UV cross-linking or not.
Hope this helps.
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Melissa Melan mmelan at lucy.wellesley.edu
Department of Biological Sciences
Wellesley College
Wellesley, MA 01281
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